Mount for electron discharge devices



Jan. 16, 1940. c., P. VOGEL MOUNT FOR ELECTRON DISCHARGE DEVCES original Filed oct. 27, 1937 INVENTOR. CHA/sl55 f? vom BY. l

ATTORNEY.A

Patented Jan. 16, 1940 PATENT OFFICE MOUNT FOR ELECTRON DISCHARGE DEVICES Charles P. Vogel, Millburn, N. J., assignor, by mesne assignments, to' Radio Corporation of America, New York, N. Y., a corporation of Delaware Original application October 27, 1937, Serial No.

171,243. Divided and this application December 13, 1938, Serial No. 245,352

lvly invention relates to improvements in electron discharge devices, and more particularly to a mount construction in which the electrode assembly is firmly held in position in the envelope of the tube. This application is a division of my bulb used in tubes made with the dome type bulb is often utilized to steady the upper end of the electrode assembly and to prevent the electrode assembly vibrating transversely of the bulb or envelope of the tube; The electrode assembly should be steadied sufficiently to avoid noises, such as clicking, which may develop in operation and which are due to contact between the electrode assembly and envelope when the tube is jarred or vibrated While in use. v

In receiving tubes where the matter of heating and high voltages is not particularly important resilient mica spacers of various kinds secured to the mount and extending between the mount and the envelope have been used to steady the mount within the envelope of the tube.

In connection with power output tubes however, it has been common practice to support mounts from the stem by a collar` construction requiring elaborate bracing. heavy side rods and a supporting collar around the stem. The spacer between the elements of the mount is of necessity one having a high insulating vcharacteristic and of substantial construction to resist high temperatures. The spacer is, therefore, usually of some ceramic material such as lavite. This material, however, cannot be used as a mount support because of its rigidity and the fact that it cannot accommodate itself to the variations of bulb diameters. The use of mica as a spacer cannot be used in such tubes inasmuch as noise results when used in amplier tubes due to leakage through the micas and because it deteriorates at the high temperatures encountered during exhaust of high power output tubes.

The object of my invention is to support the mount of a power output tube within the envelope of a tube by means of such character that it will not break down under high voltages or deteriorate at the high temperatures encountered during exhaust and at the same time provide the resiliency required for this type of support.

The novel features which I believe to be char- (Cl. Z50-27.5)

acteristic of my invention are set forth with particularity in the appended claims, but the invention itself will best be understood by reference to the following description taken in connection with the accompanying drawing in which Figure 1 is a perspective showing the mount provided with a support made according to my invention, Figure 2 is a top view of Figure l, and Figure 3 is a side view partially in section of the construction shown in Figure 1.

The electron discharge device shown in Figure 1 has a dome type envelope or bulb IB, and may be provided with the conventional base and press,

not shown. The mount I I comprising the elec trode `assembly and the supports by which the electrode assembly is carried on the stem extends into the tubular portion or dome of envelope I0. On the upper end ofthe mount is an insulator I2 which may be in the form of a cross as shown and which is preferably of some ceramic material such as'lavite for spacing the electrodes. This insulator is strong and rigid and is capable of withstanding high voltages applied between the various electrodes oi the mount and the very high temperatures of the electrodes during exhaust. In the outer ends or edges of the spacer I2 are provided slots I3 as best shown in Figures 2 and 3 for receiving the inner edges of the mica spacer I 4 provided with resilient ngers I5 contacting the inner wall of the tube envelope IIJ. As best shown in Figure 2 this ring-like mica spacer I4 is provided with a plurality of cut-out portions or sections IB, these cut-out portions being of such dimensions that the ring-like spacer can be inserted over and clear the. ends of the ceramic spacer I4 when the cut-out portions and the ends of the spacer are in registry with each other. The curves of the inner edges of the spacer I4 are formed so that the radii of the inner edges are of decreasing length moving in a clockwise direction with respect to Figure 2. When the mica spacer is inserted over the ceramic spacer and the inner edges of the mica spacer register with the transverse slots in the end of the ceramic spacer, the mica spacer may be locked in position relative to the ceramic spacer I2 by rotating the mica spacer in a counterclockwise direction. The resilient mica fingers engage the inner wall of the tubular portion vof the tube envelope to resiliently support the mount within the tube envelope.` In the position shown the mica spacer is outside of the portion of the tube subjected to high temperatures during exhaust and is also removed from those portions of the electrode mount subjected to high voltage differentials.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specific application for which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed Without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is:

l. An electron discharge device provided with an envelope having a tubular portion, a mount comprising an electrode assembly supported in said envelope and extending Within said tubular portion, a ceramic spacer secured to said mount to extend transversely of said tubular portion of the envelope for spacing and supporting the electrodes of the mount and provided with slots in its outer portions and a spacer of resilient sheet insulation mounted on said ceramic spacer with portions engaged in said slots and extending between the ceramic spacer and the envelope and in contact with the Walls of the envelope for resiliently supporting the end of the mount in a predeter nined position Within the envelope.

2. An electron discharge device provided with an envelope having a tubular portion, a mount comprising an electrode assembly supported in said envelope and extending Within said tubular portion, a cross-shaped ceramic insulating spacer secured to said mount to extend transversely of the tubular portion of the envelope for spacing and supporting the electrodes of the mount and provided with slots in its outer edges and a ringlike member of resilient sheet insulation having its inner edge engaged in said slots and extending between the ends of said ceramic insulating spacer and the Wall of the envelope and provided with iingers around its outer edge for contacting the wall of the envelope to resiliently support the end of the mount in a predetermined position Within said envelope.

3. An electron discharge device provided with an envelope having a tubular portion, a mount comprising an electrode assembly supported in said envelope and extending Within said tubular portion, a cross-shaped ceramic insulating spacer secured to said mount to extend transversely of the tubular portion of the envelope for spacing and supporting the electrodes of the mount and provided with slots in its outer edges and a ringlike member of resilient sheet insulation having its inner edge provided with oppositely disposed cut-out portions for permitting the ring-like member to be passed over the ends of the ceramic spacer to register the inner edge of the ring-like member with the slots in the outer edges of said ceramic spacer, and engaged in said slots and extending between the edges of the ceramic spacer and the Walls of the envelope and provided With ngers around its outer edge for contacting the wall of the envelope to resiliently support the end of the mount in a predetermined position Within said envelope.

4. An electron discharge device comprising an envelope having a tubular portion, a mount comprising an electrode assembly positioned in said envelope and extending Within the tubular portion, a ceramic spacer secured to said mount to extend transversely of the tubular portion of the envelope for spacing and supporting the electrodes of the mount, and a spacer of resilient sheet insulation mounted on said ceramic spacer and secured to the outer portion of said ceramic spacer and extending between the spacer and the envelope and in contact With the Walls of the envelope to resiliently support the end of the mount in a predetermined position Within the envelope.

CHARLES P. VOGEL. 

